This invention relates to contacting active materials such as adsorbents, catalysts, defoamers and ion exchangers with liquids, and their separation from them. Essentially the invention provides an inert particle coated with the functional material forming a composite that has a density somewhat less than the liquid. Said composite particles are introduced into the liquid under agitation and allowed to function; then when agitation is stopped, the composite particles collect at the top of the liquid and they can be easily separated from it.
Many liquids contain trace impurities that must be removed prior to use and/or storage. There are a number of problems associated with such processes. In order to reduce the time necessary to remove the impurity, the agent should have a high surface area and be finely divided. The contact between the liquid and the agent should be maintained with minimal effort such as moderate agitation. To accomplish such contact the density of the agent should not be substantially different from the liquid. Separation of these finely divided materials from the liquid is often difficult since they tend to agglomerate on filters and blind them.
It is an object of this invention to provide active materials in a form that provides easily achieved contact between the active material and the liquid and maintains the necessary high surface area, but allows easy separation from the liquid. It is a further object of this invention to provide the active agent as a coating on a particle that has a density less than that of the liquid.